Automatic screen printing machine



Dec. 4, 1962 Filed Aug. 13, 1959 HlsAKlcHl lcHlNosE 3,066,602

AUTOMATIC SCREEN PRINTING MACHINE 4 Sheets-Sheet l wus/ran HISAKICH/ ICHIA/USE Dec. 4, 1962 HlsAKlcHl lcHlNosE 3,066,602,

AUTOMATIC SCREEN PRINTING MACHINE Filed Aug. 15, 1959 4 Sheets-Sheet 2 l a l i L 'l I arf \7 7 3 /NvEA/roR-- H/SHKJCHI ICHI/VSE Dec. 4, 1962 HlsAKlcHl lcHlNosE 3,055,602

AUTOMATIC SCREEN PRINTING MACHINE Filed Aug. l5, 1959 4 Sheets-Sheet-3 2 IWI gli 30 33 HH lllll 3d 47 7 2 22 Z4 Y 37 l H n 31 A A u A 1740 o l m f7 J5 fm1 3+ l 1 4? 7 20 25o. 25 if L 2 INVEMTUR HI SAKLLHI ILHN/05E f WMM, s

Dec. 4, 1962 HxsAKlcHl lcHlNosE 3,066,502

AUTOMATIC scEEEN PRINTING MACHINE Filed Aug. 13, 1959 4 Sheets-Sheet 4 Eg EZ.

INVENTIDR HISKICHI IHINSE United States Patent 3,066,602 AUTOMATIC SQREEN PRENIENG MACHINE Hisakichi Ichinose, S7 Sanhaneho, Kousiien, Nishinomiya, Hyoga, Japan Filed Aug. 13, 1959, Ser. No. 333,629 Claims priority, application Japan Nov. 11, 1958 1 Claim. (Cl. 101-115) The present invention relates to a driving mechanism for intermittently moving a belt on a screen printing machine in which the speed of the drive is slow at the beginning of the movement, fast in the middle of the movement, and slow at the end of the movement.

It is an object of the present invention to provide a driving mechanism for screen printing machines in which the patterns in the screen are printed more accurately than heretofore by properly operating the driving mechanism to accurately position the belt relative to the screens, and yet to drive the belt between printings as fast as possible.

It is a further object of the present invention to provide a driving mechanism for screen printing machines which drives the belt intermittently at an average high speed, yet which does so by driving the belt slowly at the beginning of the intermittent movement, fast in the middle of the intermittent movement, and slow at the end of the intermittent movement while not causing elonga tions and contractions of the belt due to the acceleration and deceleration forces.

It is a still further object of the present invention to provide a driving mechanism which comprises a driving shaft, a driving gear mounted on said shaft and having teeth around only a portion of the circumference of the gear, a driven shaft having a first and a second portion, a driven gear mounted on the first portion of the driven shaft engageable only with the teeth on the driving gear, a rst lever arm having a radially extending slot therein on the end of said first portion of said driven shaft closest to said second portion of said driven shaft, a slider slidable in said slot, a crank shaft to one end of which said slider is eccentrically pivoted, a second lever arm having a radially extending slot therein on the other end of Said crank shaft, and a further slider in the slot in said second lever, said slot in said second lever arm extending in the diametrically opposite direction from the radially extending slot in said first lever arm, said `further slider eccentrically pivoted to said second portion of saidl driven shaft. The provision of this driving mechanism makes it possible to connect it to one of the rollers of the screen printing machine to produce the slow-fastslow motion already described.

Other and further objects of the present invention will become apparent from the following specification and claim, taken together with the -accompanying drawings, in which:

FIG. 1 is a side elevation view of an automatic screen printing machine according to this invention.

FIG. 2 is a side elevation View of the remainder of the machine of FIG. l, the gures joining each other on -line T T.

FIG. 3 is a plan view of the portion of the machine shown in FIG. l.

FIG. 4 is a plan View of the portion of the machine shown in FIG. 2.

FIG. 5 is a plan View, partly in section and on enlarged scale, of the mechanism for the machine according to this invention.

FIG. 6 is a sectional view on line VI-VI of FIG. 5.

FIG. 7 is a sectional view on line VII--VII of FIG. 5; and

FIG. 8 is a sectional view on line VIII- VIII of FIG. 5.

FIGS. l to 4 show the automatic screen printing machine to be equipped with this invention. Frame 1 extends the entire length of this machine, at one end of which is a driving roller 2, at the other end is a following roller 3. Between these rollers is stretched an endless belt 4 in such a way that the said belt 4 may be intermittently advanced in the direction shown .by the arrow mark by intermittent revolutions of a driving roller 2. In this way, the following roller 3 is also revolved intermittently. Above this endless belt 4, a plurality of printing frames 5 are arranged (FIGS. 2 and 4 show l0 printing frames) and all of them are held by main frame 6. Extending in the transverse direction of the said main frame 6 are several guide rails '7 (FIGS. 2 and 4 show 6 guide rails), on which squeegee holders 8 are placed so as to be movable reciprocally in the transverse direction of printing frames at the required time. These squeegee holders can be joined to each other throughout the full length of the frame, or occasionally a few of them can be mounted to move independently of the others. From these squeegee holders, two or more squeegees are hung in each printing frame so as to come in contact with screens which are stretched across the bottom of each printing frame. Coior paste is stored between the said squeegees to print cloth through the screen 56 when the squeegee slides on the screens. At the entry end of the frame 1, the feed ing device 9 for cloth 51 to be printed is installed so that the cloth 51 is continuously fed from the entry to the exit, being agglutinated on the endless belt in accordance with the advances of endless belt. At the exit of the frame, the dryer 1li is installed for the after-treatment of printed cloth as shown in FIGS. l and 3. The dryer 1G is equipped with a cloth discharge apparatus 11.

FIGS. 5 to 8 show the mechanism for providing the intermittent motion which is installed at the left end of FIG. 4 and constitutes an essential part of this machine according to the invention.

Referring to FIG. 5, there is shown a simple and accurate driving mechanism. Casing 17 has shafts 1S, 19, 20, 21 and 22 mounted in parallel therein. Shaft 18 is coupled at one end thereof with the driving roller 2 through gears 23 and 24 and is coupled at the other end with shaft 19 through gears 25 and 26. The driving shaft 2Q is coupled with shafts 19 `and 21 through an intermittent rnotion device having gears 28 and 39 meshing with gears 27 and 33 which have teeth only part way around the circumference thereof. Gears 27 and 38 are secured together on a common hub shaft 22 through gears 28a and 29 and clutch 32, or through gears 30 and 31 and1 clutch 32. Clutch 32 couples either gears 28a and 29' to shaft 22 or gears 30 and 31 to shaft 22 so that the intermittent revolutions of shaft 21 are transmitted to shaft 22 at either one of two speeds. Furthermore, one end of shaft 22 projects from casing 17. The projecting end is directly coupled with elements 33 and 34 which may `actuate frame 6 holding printing frames 5 and squeegee holders 8. One end of driving shaft 20 is connected by a gear 36 to an electric motor 35 (FIGS. 2 and 4) and the other end has sprocket wheel 37 thereon to deliver power to the squeegee moving mechanism or the mother frame. The gear 38 is engaged with a gear 39 having a projection 39a thereon engageable with the smooth portion of gear 38. Gear 39 is mounted on the shaft 47 which is supported in bearings 46 at both ends and has a disc 40 on one end thereof.

Gear 33 and gear 39 are engageable either through the untoothed portion of gear 38 and the projection 39a on gear 39, or through the teeth on the two gears. When the concave end on projection 39a is engaged with the untoothed portion :of gear 33, the gear 39 is held in the proper rotational position where the teeth thereon will be engaged by the teeth on gear 38 when the teeth on gear 3 38 again come around to the point adjacent gear 39. When the teeth of both gears are engaged, power is delivered to the driven gear 39 which is driven at a uniform velocity during a certain period of time which is in proportion to the number lof teeth in engagement. This produces the intermittent motion described hereinbefore.

A lever in the form of disc 40 mounted on one end of shaft -47 driven by the gear 39 has a radial slot 41 cut Itherein. Crank pin 43 on crank 45 on the crank shaft 44 is guided in the said slot 41, either directly or indirectly through a slider 42 on crank pin 43 as sho-wn in FIGS. 6, 7 and 8. Since the axis of crank shaft 44 is parallel to that of shaft 47 for the driven gear 39, the angular velocity during one revolution or shaft 47 produces nonuniform rotary motion of shaft 44 due to the eccentric position of shaft 47 and the sliding of the crank pin 43 in the slot 41. In other words, irrespective of the amount of the eccentricity, `the initial and final velocities during one revolution of the shaft 44 may be kept low and the intermediate velocity within one revolution of the said shaft may effectively be increased. By means of this slider crank mechanism, the intermittent motion of disc 40 may satisfactorily be .transmitted through the said slider crank mechanism from the disc 40 to the crank shaft 44.

Furthermore, the motion of crank shaft 44 may either directly be conveyed to the driving roller 2 through gear 25, shaft 18 and gears 23 and 24 by omitting `the lever in `the form of disc 48 and crank 49 (this modification is not shown), or to shaft 18 and driving roller 2 through a lever in the fo-rm `of a disc 48 similar to disc 40, a slider 48a, crank pin 50 and crank 49 which are mounted between shaft 19 and crank shaft 44 in the mechanism as shown in FIGS. 6, 7 and 8. This structure produces a greater variation between the initial and intermediate speeds.

The structures of driving gear 27 on driving shaft 20 and driven gear 28 on shaft 21, are quite similar to those of driving and driven gears 38 and 39 described hereinbefore. Through these gears, shaft 21 is intermittently rotated in a manner similar to the intermittent revolutions of shaft 47 and driving roller 2 connected to shaft 47.

Accordingly, the motion of the driving roller and elements 33 and 34 governing the motions of the mother frame, printing frames and the squeegees is correlated with the motion rof the belt.

As described hereinbefore, the initial and final velocities during one revolution of the shaft 44 may be slow and the intermediate velocity within one revolution of the said shaft may be fast, irrespective of the amount of the eccentricity.

Accordingly, endless rubber belt y4 is also moved intermittently when the driving roller 2 and other driving parts are rotated through the gear system consisting of both gears 38 and 39 and through the slider crank mechamsm.

The speed variation is one of the most essential functions of this printing apparatus according to the invention. With the speed variation a cloth to be printed on the endless rubber belt can be moved to the next printing kframe 5 slowly at first, then fast and finally slowly. With this motion, a cloth may be set accurately under the next printing frame on which the next elementary pattern may be printed.

This invention may effectively be used .to accomplish `accurate and ingenious printing by preventing slips in patterns due to the elongation and contraction o-f the endless rubber belt because both undue `stress and slackening of the said belt are satisfactorily prevented by the elements of the machine.

It is thought that the invention and its advantages will be understood from the foregoing description and it is apparent that vario-us changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing its material advantages, the form hereinbefore described and illustrated in .the drawings being merely a preferred embodiment thereof.

What I claim is:

A driving mechanism for one of the rollers in an automatic screen printing machine having a frame, rollers at opposite ends of said frame and an endless rubber belt around said rollers for supporting the cloth to be printed, said driving mechanism comprising a driving shaft, a driving gear mounted on said shaft having teeth around only a portion of the circumference thereof, a driven shaft having a first and a second portion, a driven gear mounted on said first portion of said driven shaft engagea'ble only with the teeth on said driving gear, a first lever arm having a radially extending slot therein on the end of said first portion of said driven shaft closest to said second p0rtion of said driven shaft, a slider slidable in said slot, a crank shaft to one end of which said slider is eccentrically pivoted, a second lever arm having a radially extending slot therein on .the other end of said crank shaft, and a further slider in the slot in said second lever, said slot in said second lever arm extending in the diametrically opposite direction from the radially extending slot in said first lever arm, said further slider eccentrically pivoted to said `second portion of said driven shaft; whereby said driving mechanism is adapted to be connected to one o-f said rollers for intermittently driving the roller so that the speed of the roller is slow at the beginning of the movement, fast in `the middle of the movement, and slow at the end of the movement.

References Cited in the file of this patent UNITED STATES PATENTS uw v. im 

